#!/usr/bin/env python
#
# Copyright 2012 New Dream Network (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Test base classes.
"""
import functools
import os.path

import eventlet
import oslo.messaging.conffixture
from oslo.utils import timeutils
from oslotest import base
from oslotest import mockpatch
import six
from testtools import testcase
import webtest

import ceilometer
from ceilometer import messaging


class BaseTestCase(base.BaseTestCase):
    def setup_messaging(self, conf, exchange=None):
        self.useFixture(oslo.messaging.conffixture.ConfFixture(conf))
        conf.set_override("notification_driver", "messaging")
        if not exchange:
            exchange = 'ceilometer'
        conf.set_override("control_exchange", exchange)

        # NOTE(sileht): oslo.messaging fake driver uses time.sleep
        # for task switch, so we need to monkey_patch it
        # and also ensure the correct exchange have been set
        eventlet.monkey_patch(time=True)

        # NOTE(sileht): Ensure a new oslo.messaging driver is loaded
        # between each tests
        self.transport = messaging.get_transport("fake://", cache=False)
        self.useFixture(mockpatch.Patch(
            'ceilometer.messaging.get_transport',
            return_value=self.transport))

    def assertTimestampEqual(self, first, second, msg=None):
        """Checks that two timestamps are equals.

        This relies on assertAlmostEqual to avoid rounding problem, and only
        checks up the first microsecond values.

        """
        return self.assertAlmostEqual(
            timeutils.delta_seconds(first, second),
            0.0,
            places=5)

    def assertIsEmpty(self, obj):
        try:
            if len(obj) != 0:
                self.fail("%s is not empty" % type(obj))
        except (TypeError, AttributeError):
            self.fail("%s doesn't have length" % type(obj))

    def assertIsNotEmpty(self, obj):
        try:
            if len(obj) == 0:
                self.fail("%s is empty" % type(obj))
        except (TypeError, AttributeError):
            self.fail("%s doesn't have length" % type(obj))

    @staticmethod
    def path_get(project_file=None):
        root = os.path.abspath(os.path.join(os.path.dirname(__file__),
                                            '..',
                                            '..',
                                            )
                               )
        if project_file:
            return os.path.join(root, project_file)
        else:
            return root


def _skip_decorator(func):
    @functools.wraps(func)
    def skip_if_not_implemented(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except ceilometer.NotImplementedError as e:
            raise testcase.TestSkipped(six.text_type(e))
        except webtest.app.AppError as e:
            if 'not implemented' in six.text_type(e):
                raise testcase.TestSkipped(six.text_type(e))
            raise
    return skip_if_not_implemented


class SkipNotImplementedMeta(type):
    def __new__(cls, name, bases, local):
        for attr in local:
            value = local[attr]
            if callable(value) and (
                    attr.startswith('test_') or attr == 'setUp'):
                local[attr] = _skip_decorator(value)
        return type.__new__(cls, name, bases, local)
